Rescue helicopters allow for quick access to injured or isolated patients on sea or land. More times than not, the patients are injured or have a medical emergency that warranted the local or federal authorities to authorize the use of an expensive helicopter hoisting operation. During these operations, however, hoisting extractions are subject to winds and other external factors that cause the rescue hoist to spin and swing back and forth. This swinging complicates the mission, causes delays in medical care, and has led to deaths both of rescuers and the rescuees.
In modern helicopter hoist, rescue, and sling load operations there is often unstable, hazardous motion of the suspended person or equipment that endangers the operation at hand and, more importantly, the people involved. The observed motion is comparable to a lateral or conical pendulum, with rotation about the hinge pivot point. A mission-critical attribute of the hoist system operability remains unsolved: reliable stability of slung cable motion. Uncontrolled cable motion endangers lives, jeopardizes mission success, sacrifices mission opportunities due to environmental elements, and drastically increases operational costs.